CN107701913B

CN107701913B - High-pressure tank

Info

Publication number: CN107701913B
Application number: CN201611160847.1A
Authority: CN
Inventors: 李东善
Original assignee: Hyundai Motor Co; Kia Motors Corp
Current assignee: Hyundai Motor Co; Kia Corp
Priority date: 2016-08-09
Filing date: 2016-12-15
Publication date: 2021-07-13
Anticipated expiration: 2036-12-15
Also published as: JP6994829B2; JP2018025287A; KR20180017377A; US11333300B2; US20180045371A1; CN107701913A; DE102016225194A1

Abstract

The present application provides a high pressure tank. The high-pressure tank provides improved strength and rigidity by optimizing the laminate pattern and structure of fiber reinforced plastic forming a hemispherical portion of the high-pressure tank in a fuel tank for a fuel cell vehicle. The fiber reinforced plastic having a higher strength is mixed and used for a weaker portion of the hemispherical portion of the support layer of the high-pressure tank where stress is concentrated due to the internal pressure of the high-pressure tank. In particular, the breaking strength and rigidity are increased. The amount of fiber reinforced plastic used, the number of wraps, and the thickness are reduced by directly reinforcing the weaker points of the hemispherical sections. Therefore, the manufacturing cost of the high-pressure tank is reduced.

Description

High-pressure tank

Technical Field

The present application relates to a high-pressure tank, and more particularly, to a high-pressure tank that provides improved strength and rigidity reinforcement by optimizing a laminate pattern and structure of fiber reinforced plastic (fiber reinforced plastic) forming the tank.

Background

Generally, a fuel cell vehicle using hydrogen as fuel includes a high-pressure fuel tank for storing hydrogen in the form of high-pressure gas. The high pressure fuel tank includes an inner liner layer that blocks permeation of gases and an outer support layer that supports internal tank pressure. The backing layer is formed from a plastics material and the support layer is formed from an expensive fibre reinforced plastics material.

For example, carbon fiber reinforced plastics used for a support layer of a high-pressure fuel tank are composite materials formed using carbon fibers as reinforcing fibers. Carbon fiber reinforced plastics can be used to make composites that are lightweight and have improved strength and elasticity. However, carbon fiber reinforced plastics are expensive materials with increased costs when compared to carbon steel. Fiber reinforced plastics are anisotropic materials with different strengths based on the laminated pattern of fibers. When the lamination pattern becomes poor, high strength cannot be obtained even in the case of using a large amount of material.

The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person skilled in the art.

Disclosure of Invention

Provided is a high-pressure tank having improved strength and rigidity reinforcement by optimizing the lamination pattern and structure of a fiber reinforced plastic for forming a hemispherical portion of the high-pressure tank used in a fuel tank of a fuel cell vehicle or the like.

In an exemplary embodiment, the high-pressure tank may include a support layer having an outer layer of the high-pressure tank and including a cylindrical body portion at a middle portion thereof. The hemispherical portions may be formed at both sides of the cylindrical portion. The hemispherical portion may include a small angle inner helical portion forming an inner layer and a small angle outer helical portion which may form an outer layer. The low angle internal helical layer portion comprises a plurality of low angle internal helical layers. At least one of the plurality of low-angle internal helical layers may be a high-strength low-angle internal helical layer having greater rigidity than the low-angle internal helical layer.

In an exemplary embodiment, the low angle internal helical layer portion may be formed in a thickness region corresponding to about 5% to 30% of the overall thickness of the hemispherical portion. The low-angle outer helical layer portion may be formed in an area of thickness corresponding to about 70% to 95% of the overall thickness of the hemispherical portion. In an exemplary embodiment, a portion of the plurality of small-angle inner helical layer portions may be high-strength small-angle inner helical layers having greater rigidity than the remaining small-angle inner helical layers, which may be low-strength small-angle inner helical layers.

For example, a high strength small angle inner helical layer may be provided as an inner layer of a small angle inner helical layer portion. The low-strength, low-angle inner helical layer may be disposed as an outer layer of a portion of the low-angle inner helical layer. In another exemplary embodiment, the high-strength small-angle inner helical layer may be disposed as an outer layer of a portion of the small-angle inner helical layer. The low-strength, low-angle inner helical layer may be disposed as an inner layer of a portion of the low-angle inner helical layer.

In certain exemplary embodiments, the high-intensity small-angle internal spiral layer and the low-intensity small-angle internal spiral layer may be disposed in a mixed manner without limiting the lamination order of the layers, or may be disposed in a mixed manner in which the layers are alternately laminated with each other. According to an exemplary embodiment, a fiber reinforced plastic, which is improved compared to conventional plastics, is mixed and used for a weaker part of a hemispherical portion of a support layer of a high-pressure tank, on which weak part stresses caused by pressure inside the tank are concentrated. The bursting strength (bursting strength) and the rigidity can be increased, and the amount of the fiber-reinforced plastic used can be reduced. The number of times of winding can be reduced by directly reinforcing the weak point of the hemispherical portion, and the manufacturing cost of the high-pressure tank can be reduced.

The hemispherical portion is formed by winding a fiber reinforced plastic around an outer surface of the liner layer, and wherein the metal flange is disposed at an acute angle in a predetermined range with respect to a direction of a central axis of the high-pressure tank.

Drawings

The above and other features of the present application will be described in detail hereinafter with reference to exemplary embodiments of the present application, given by way of illustration and thus not limiting in the accompanying drawings, in which:

FIG. 1 is an exemplary cross-sectional view illustrating a high pressure tank according to an exemplary embodiment of the present application;

fig. 2 is an exemplary enlarged view illustrating a portion a of fig. 1 according to an exemplary embodiment of the present application;

fig. 3 is an exemplary enlarged view illustrating a portion B of fig. 1 according to an exemplary embodiment of the present application;

4A-4H are exemplary views illustrating small-angle inner helical layer portions according to exemplary embodiments of the present application;

fig. 5 is an exemplary enlarged view illustrating a portion C of fig. 1 according to an exemplary embodiment of the present application.

Fig. 6A to 6C are exemplary conceptual views showing types of winding patterns for a high-pressure tank according to an exemplary embodiment of the present application;

FIG. 7 is an exemplary graph showing burst pressure of a high pressure tank relative to the location of a high strength small angle inner spiral layer formed by winding a high strength fiber reinforced plastic according to an exemplary embodiment of the present application; and

fig. 8 is an exemplary graph showing burst pressure of a high-pressure tank with respect to a use area of a thickness area of a hemispherical portion using a high-strength small-angle inner spiral layer according to an exemplary embodiment of the present application.

The reference numerals listed in the drawings include references to the following elements which will be discussed further below:

100: high-pressure tank

110: cushion layer

112: metal flange

120: supporting layer

122: cylindrical body part

122 a: hoop layer

122 b: spiral layer

124: hemispherical segment

126 a: small angle inner spiral layer part

126 aa: high-strength small-angle inner spiral layer

126 ab: low-strength small-angle inner spiral layer

126 b: small angle external spiral layer part

128: transition section

It should be understood that the drawings are not necessarily to scale, showing features that are somewhat simplified to illustrate the basic principles of the application. The specific design features of the present application, including, for example, specific dimensions, orientations, locations, and shapes, disclosed herein will be determined in part by the particular intended application and use environment. In the figures, reference numerals designate identical or equivalent parts throughout the several views of the drawings.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the present application, examples of which are illustrated in the accompanying drawings and described below. While the present application is described in conjunction with the exemplary embodiments, it should be understood that this description is not intended to limit the present application to those exemplary embodiments. On the contrary, the application is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents and other exemplary embodiments that may be included within the spirit and scope of the application as defined by the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates to the contrary. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. For example, irrelevant portions are not shown for clarity of the description of the application, and the thickness and area of layers are exaggerated for clarity. Further, when a layer is recited as being "on" another layer or substrate, the layer may be directly on the other layer or substrate, or a third layer may be interposed therebetween.

It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless otherwise indicated or apparent from the context, the term "about" as used herein is to be understood as being within the normal tolerance in the art, e.g., 2 standard deviations of the mean. "about" can be understood as being within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the stated value. All numerical values provided herein are modified by the term "about," unless the context clearly dictates otherwise.

It should be understood that the term "vehicle" or "vehicular" or other similar terms as used herein generally includes motor vehicles such as passenger automobiles including Sport Utility Vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats, ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from non-petroleum sources). As referred to herein, a hybrid vehicle is a vehicle having two or more power sources, for example, both gasoline-powered and electric-powered vehicles.

Exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. As shown in fig. 1, the high-pressure tank 100 according to the present application may include: a backing layer 110 which is an inner layer and can block or block permeation of fuel in the form of high-pressure gas; a support layer 120 which is an outer layer and supports the internal pressure of the tank; and a metal flange (boss)112 integrally provided at an inlet side of the gasket layer 110, the inlet side being coupled to an opening and closing valve (not shown).

The cushion layer 110 may be formed by injection molding a plastic material. The metal flange 112 may be integrally formed on the inlet side of the cushion layer 110 by inserting the metal flange 112 into an injection mold and performing injection molding. The support layer 120 may be formed by a winding lamination method (winding lamination method) of winding and laminating fiber reinforced plastic around the outer surface of the cushion layer 110, and may include a cylindrical body portion 122 in the middle thereof. The hemispherical portions 124 may be integrally formed at both sides of the cylindrical body portion 122. The cylindrical body portion 122 may be a substantially straight section of the high pressure tank 100, and may be formed in a cylindrical shape along an outer shape of a middle portion of the gasket layer 110. As shown in fig. 2, the cylindrical body part 122 may have a cross-sectional structure in which hoop layers 122a and spiral layers 122b are alternately laminated, the hoop layers 122a and spiral layers 122b being laminated by winding fiber reinforced plastic around the outer surface of the middle portion of the cushion layer 110.

In particular, each of the hoop layer 122a and the spiral layer 122b may be formed by winding the fiber reinforced plastic around the outer surface of the backing layer 110 once, or may be formed by winding the fiber reinforced plastic around the outer surface of the backing layer 110 several times. In other words, each of the hoop layer 122a and the spiral layer 122b shown in fig. 2 may be formed by winding the fiber reinforced plastic around the outer surface of the cushion layer 110 at least once. The configuration in which the hoop layer 122a is disposed in the inner layer region of the thickness region of the support layer 120 and laminated more adjacent to the gasket layer 110 may be advantageously used to increase the rupture strength of the high-pressure tank 100. Accordingly, the hoop layer 122a and the spiral layer 122b of the cylindrical body portion 122 may be first laminated on the outer surface of the middle portion of the cushion layer 110 to be in contact with (e.g., directly) the outer surface of the middle portion of the cushion layer 110.

Referring to fig. 6A through 6C, the hoop layer 122a may be formed by laminating in a winding pattern in which fiber reinforced plastic may be wound around the outer surface of the liner layer 110. In other words, the fiber reinforced plastic may be wound at about a right angle with respect to the direction L of the central axis of the high-pressure tank 100 (e.g., the axial direction of the liner layer 110). The spiral layer 122b may be formed by laminating in such a winding pattern: the fiber reinforced plastic wound around the outer surface of the liner layer 110 is wound at an acute angle within a predetermined range with respect to the direction L of the central axis of the high-pressure tank 100.

In particular, the hoop layer 122a may be formed by laminating in such a hoop pattern: wherein the fiber reinforced plastic is wound at an angle of about 89 ° with respect to the direction L of the central axis of the high-pressure tank 100. The spiral layer 122b may be formed by laminating in a large-angle spiral pattern in which the fiber reinforced plastic is wound at an acute angle of about 45 ° to 88 ° with respect to the direction L of the central axis of the high-pressure tank 100 or a small-angle spiral pattern in which the fiber reinforced plastic is wound at an acute angle of about α to 44 ° with respect to the direction L of the central axis of the high-pressure tank 100. For example, α may be the minimum wrap angle of the fiber reinforced plastic, and α may be based on the outer diameter z of the backing layer 110Value and outer diameter r of metal flange 112_bIs determined. In other words, the minimum winding angle of fiber reinforced plastics forming a small-angle helical pattern may be based on α ═ sin^-1(r_bZ) is determined.

The hemispherical portion 124 may be an arc-shaped section of the high pressure tank 100, and may be formed in an approximately hemispherical shape along the outer shape of both end portions of the liner layer 110. As shown in fig. 3, the hemispherical portion 124 may be formed by winding the fiber reinforced plastic around outer surfaces of both end portions of the backing layer 110 (e.g., the outer surfaces of both end portions of the backing layer 110 and the outer surface of the metal flange 112) several times. In particular, for the hemispherical portion 124, in order to directly enhance rigidity and strength, enhance fracture rigidity and strength without increasing the thickness of the hemispherical portion or using a separate reinforcing member, when the hemispherical portion 124 is formed by winding a fiber reinforced plastic, a fiber reinforced plastic having higher strength may be used for a selected local area.

Further, the hemispherical portion 124 may include a small-angle inner spiral layer portion 126a as an inner layer and a small-angle outer spiral layer portion 126b as an outer layer, based on the thickness direction of the hemispherical portion 124. The fiber reinforced plastic may have a high rigidity and strength and may be used for the small-angled inner spiral layer portions 126a adjacent to the outer surfaces of both ends of the liner layer 110 and the outer surface of the metal flange 112. The small-angle inner helical layer portion 126a may include a plurality of small-angle inner helical layers. At least one of the small-angle inner spiral layers may be formed using a fiber reinforced plastic having greater rigidity and strength than the fiber reinforced plastics of the other small-angle inner spiral layers.

In other words, the small-angle inner spiral layer portion 126a may include at least one high-strength small-angle inner spiral layer 126aa formed by wrapping (which may be more rigid and stronger than the fiber-reinforced plastic of the small-angle outer spiral layer portion 126b and may be more rigid and stronger than the fiber-reinforced plastic of other small-angle inner spiral layers (e.g., low-strength small-angle inner spiral layers)) fiber-reinforced plastic around the outer surfaces of the liner layer 110 and the metal flange 112. For example, the low-strength small-angle inner helical layer 126ab and the high-strength small-angle inner helical layer 126aa may be formed by wrapping fiber reinforced plastic around the outer surfaces of the gasket layer 110 and the metal flange 112.

Since a fiber reinforced plastic having high strength and high rigidity can be used for the small-angle inner spiral layer portion 126a of the hemispherical portion 124 at least partially as an inner layer, the amount of use of a high-priced high-strength fiber reinforced plastic can be reduced, and the reinforcing strength and rigidity of the hemispherical portion 124 can be improved. When the hemispherical portion 124 is formed in a multi-layer shape by winding the fiber reinforced plastic around the outer surfaces of both end portions of the backing layer 110 and the outer surface of the metal flange 112, the small-angle inner spiral layer portion 126a may be formed by winding the fiber reinforced plastic.

The small angle outer helical portion 126b may be formed by wrapping a fiber reinforced plastic. In particular, the hemispherical portion 124 has a small-angled inner spiral layer portion 126a, which may be formed in an inner layer region adjacent to the outer surface of the backing layer 110 in the thickness direction of the hemispherical portion 124. The small-angle outer spiral layer portion 126b may form an outer layer region in the thickness direction of the hemispherical portion 124 by being laminated on the outer side of the small-angle inner spiral layer portion 126 a.

Typically, the inner region of the hemispherical portion 124, where the fibre reinforced plastic is first wound around the outer surface of the liner layer 110, is structurally affected by the internal pressure of the high pressure tank 100, as compared to the outer region. Therefore, the inner layer region becomes weak due to stress concentrated on the inner layer region. However, since the small-angle inner spiral layer portion 126a including at least one high-strength small-angle inner spiral layer 126aa may be formed in the inner layer region of the hemispherical portion 124 as described above, the strength of the weaker portion of the hemispherical portion 124 may be improved.

In other words, the entire strength of the hemispherical portion 124 can be enhanced by using the fiber reinforced plastic having higher strength and rigidity at least in a partial area of the hemispherical portion 124. In particular, since a fiber reinforced plastic having enhanced strength and enhanced rigidity may be used for the small-angle inner spiral layer part 126a constituting the inner layer region of the hemispherical portion 124, the strength of the hemispherical portion 124 may be enhanced more effectively than a fiber reinforced plastic having high strength and high rigidity used for the small-angle outer spiral layer part 126 b.

Generally, the number of laminated layers (e.g., number of wraps) of fiber reinforced plastic may be increased to improve the weaker point of hemispherical portion 124, and thus increase the thickness of the hemispherical portion. When the number of laminated layers of the fiber reinforced plastic is merely increased, the reinforcing effect is insufficient as compared with the amount of the fiber reinforced plastic used. Therefore, it may be necessary to use a large amount of fiber reinforced plastic, which results in a significant increase in manufacturing costs.

Therefore, as described above, since the small-angle inner spiral layer portion 126a in the inner layer region, which is a structurally weaker portion of the hemispherical portion 124, is formed using the fiber reinforced plastic having higher rigidity and strength than the fiber reinforced plastic of the small-angle outer spiral layer portion 126b, it is possible to prevent stress concentration on the hemispherical portion 124. Further, the amount of fiber reinforced plastic used can be reduced compared to the related art, thereby reducing the thickness of the hemispherical portion 124 and ensuring the same level of reinforcement effect as a typical hemispherical portion (for example, a hemispherical portion made of a single fiber reinforced plastic).

Further, a detailed structure of the small-angle inner spiral layer portion 126a will be described by referring to fig. 4A to 4H. Fig. 4A through 4D are views illustrating a small-angle inner helical layer portion 126a according to an exemplary embodiment of the present application. As shown in fig. 4A-4C, the small-angle inner helical layer portion 126a may include a plurality of small-angle inner helical layers. One of the plurality of small-angle inner spiral layers may be configured as a high-strength small-angle inner spiral layer 126aa having greater rigidity and strength than the other small-angle inner spiral layers. In other words, the high-strength small-angle inner helical layer 126aa may be disposed as the lowest layer of the small-angle inner helical layer portion 126a and may be in contact (e.g., directly) with the outer surface of the cushion layer 110 and the outer surface of the metal flange 112, as shown in fig. 4A. The high-strength small-angle inner spiral layer 126aa may be provided as the uppermost layer of the small-angle inner spiral layer portion 126a, as shown in fig. 4B, or may be provided as any layer between the lowermost layer and the uppermost layer, as shown in fig. 4C.

As shown in fig. 4D and 4E, two or more of the plurality of small-angle inner spiral layers of the small-angle inner spiral layer portion 126a may be high-strength small-angle inner spiral layers 126aa having greater rigidity and strength than the remaining small-angle inner spiral layers. In other words, some of the plurality of small-angle inner spiral layers of the small-angle inner spiral layer portion 126a may be high-strength small-angle inner spiral layers 126 aa. The remaining low-angle inner spiral layers may be low-strength low-angle inner spiral layers 126 ab.

In other words, based on the thickness direction of the small-angle inner spiral layer portion 126a, all of the high-strength small-angle inner spiral layers 126aa may be disposed in the inner layer region of the small-angle inner spiral layer portion 126a, and all of the low-strength small-angle inner spiral layers 126ab may be disposed in the outer layer region of the small-angle inner spiral layer portion 126a (fig. 4D). Alternatively, the high-strength small-angle inner spiral layer 126aa may be disposed in an outer layer region of the small-angle inner spiral layer portion 126a based on the thickness direction of the small-angle inner spiral layer portion 126 a. A low-strength, low-angle, inner helical layer 126ab may be disposed in the inner layer region of the low-angle, inner helical layer portion 126a, as shown in fig. 4E.

In other words, the overall thickness of the high-strength small-angle inner helical layer 126aa may be equal to or different than the overall thickness of the low-strength small-angle inner helical layer 126 ab. As shown in fig. 4F to 4G, in the small-angle inner spiral layer portion 126a, a plurality of high-strength small-angle inner spiral layers 126aa and a plurality of low-strength small-angle inner spiral layers 126ab may be provided in a mixed manner without limiting the lamination order of the layers (e.g., the order of winding the fiber reinforced plastic). The high-strength small-angle inner spiral layer 126aa and the low-strength small-angle inner spiral layer 126ab may be provided in a mixed manner, wherein the high-strength small-angle inner spiral layer 126aa and the low-strength small-angle inner spiral layer 126ab may be laminated to each other continuously and alternately. In particular, the high-strength small-angle inner helical layer 126aa or the low-strength small-angle inner helical layer 126ab may be disposed as the lowermost layer of the small-angle inner helical layer portion 126 a.

As shown in fig. 4H, all of the plurality of small-angle inner spiral layers of the small-angle inner spiral layer portion 126a may be high-strength small-angle inner spiral layers 126 aa. In particular, the low-angle inner helical layer (e.g., high-strength low-angle inner helical layer and low-strength low-angle inner helical layer) of the low-angle inner helical layer portion 126a may be formed by laminating in such a winding pattern: wherein the fiber reinforced plastic wound around the outer surface of the liner layer 110 may be wound at an acute angle in a predetermined range with respect to the direction L of the central axis of the high pressure tank 100. In particular, the small-angle inner helical layer may be formed by laminating with fiber reinforced plastic in a small-angle helical pattern wound at an acute angle of about α to 44 ° with respect to the direction L of the central axis of the high pressure tank 100, as shown in fig. 6C. When the small-angle inner bolt layer is wound as described above, a part of the spiral layer of the cylindrical body portion 122 may be formed at the same time.

The small-angle inner spiral layer portion 126a and the small-angle outer spiral layer portion 126b may be formed using various fiber reinforced plastics (e.g., a composite material using carbon fibers as reinforcing fibers and a composite material using glass fibers as reinforcing fibers). Some of the small-angle inner spiral layers 126a may be formed by using a fiber reinforced plastic having greater rigidity and strength than the fiber reinforced plastic of the other small-angle inner spiral layers and small-angle outer spiral layers. Therefore, the thickness of the hemispherical portion 124 and the amount of fiber reinforced plastic used can be reduced. In addition, the weight and manufacturing cost of the high-pressure tank may be reduced, and fuel weight efficiency (fuel weight efficiency) may be improved due to the reduction in weight of the high-pressure tank 100. The fuel supply amount stored in the high-pressure tank 100 may be increased, and thus the distance that the vehicle may travel may be increased.

Because at least one of the plurality of small-angle inner spiral layers forming the small-angle inner spiral layer portion 126a of the hemispherical portion 124 may be a high-strength small-angle inner spiral layer 126aa, an inner layer region (e.g., the small-angle inner spiral layer portion) of the hemispherical portion 124 may have greater burst strength and rigidity than an outer layer region (e.g., the small-angle outer spiral layer portion). In the hemispherical portion 124, about 5% to 30% of the entire thickness of the small-angle inner spiral layer portion 126a as the inner layer and the small-angle outer spiral layer portion 126b as the outer layer may be formed as the small-angle inner spiral layer portion 126a, and about 70% to 95% of the entire thickness may be formed as the small-angle outer spiral layer portion 126 b.

When the thickness of the small-angle inner spiral layer portion 126a is less than about 5% of the entire thickness of the hemispherical portion 124, it may be difficult to increase the strength and rigidity of the hemispherical portion 124 to a desired level. In addition, when the thickness of the small-angle inner spiral layer portion 126a is greater than about 30% of the entire thickness of the hemispherical portion 124, the effect of enhancing the strength and rigidity of the hemispherical portion 124 with respect to cost is not improved. Generally, since the fiber reinforced plastic having greater strength and greater rigidity is expensive, it is necessary to increase the strength and rigidity of the hemispherical portion 124 while minimizing the amount of the fiber reinforced plastic having high strength.

In other words, it is possible to increase the strength and rigidity of the hemispherical portion 124 to a desired level even in the case where the thickness of the small-angle inner helical layer portion 126a including the high-strength small-angle inner helical layer 126aa is greater than about 30% of the entire thickness of the hemispherical portion 124. In other words, even if the high-strength small-angle inner spiral layer 126aa is disposed in an area exceeding about 30% of the entire thickness of the hemispherical portion 124, the strength and rigidity of the hemispherical portion 124 can be increased to a desired level. However, when the thickness of the small-angle inner spiral layer portion 126a is greater than about 30% of the entire thickness of the hemispherical portion 124, the effect of reinforcing the hemispherical portion 124 is not improved with respect to the amount of use and material cost of the fiber reinforced plastic.

The hemispherical portion 124 may structurally increase in thickness at a portion closer to the metal flange 112, and thus, the small angle internal helical portion 126a may also increase in thickness. Further, as shown in fig. 5, a transition portion 128, which is a section where the hoop layer 122a of the cylindrical body portion 122 terminates, may be disposed between the hemispherical portion 124 and the cylindrical body portion 122. A cylindrical body portion 122, which is a straight section of the support layer 120, and a hemispherical portion 124, which is an arc section, are connected to each other at a transition portion 128.

In order to monitor the effect of an increase in the rupture pressure (e.g., rupture strength) of the high-pressure tank when the strength and rigidity of the hemispherical portion are enhanced according to the present application, a high-pressure tank in which the hemispherical portion of the support layer is manufactured by using a single fiber reinforced plastic (comparative example 1) and a high-pressure tank in which the hemispherical portion of the support layer is manufactured by using a heterogeneous fiber reinforced plastic (examples 1 and 2) were prepared. Further, the burst pressure of the high-pressure tank according to comparative example 1 and the burst pressures of the high-pressure tanks according to examples 1 and 2 were measured. The measurement results are shown in table 1 below.

In particular, the high-pressure tanks according to examples 1 and 2 and the high-pressure tank according to comparative example 1 were manufactured under the same conditions, except that the hemispherical portions of the support layers of the high-pressure tanks according to comparative example 1 were formed using a low-strength fiber-reinforced plastic having a strength of 2550MPa and a rigidity of 135 GPa. The hemispherical portions of the support layers of the high-pressure tanks according to examples 1 and 2 were formed by mixing and using a high-strength fiber reinforced plastic having a strength of 3040MPa and a rigidity of 159GPa and a low-strength fiber reinforced plastic having a strength of 2550MPa and a rigidity of 135 GPa.

However, the high-pressure tank according to example 1 was manufactured by using a high-strength fiber reinforced plastic for a thickness region corresponding to 5% of the entire thickness of the hemispherical portion and adjacent to the gasket layer. The low-strength fiber reinforced plastic is used for the remaining thickness region corresponding to 95% of the entire thickness of the hemispherical portion, and the high-pressure tank according to example 2 is manufactured by using the high-strength fiber reinforced plastic for the uppermost layer (e.g., the outermost layer) in the thickness region corresponding to 30% of the entire thickness of the hemispherical portion and adjacent to the cushion layer. The low-strength fiber reinforced plastic is used for the remaining thickness region corresponding to 70% of the entire thickness of the hemispherical portion.

TABLE 1

As shown in table 1, the high-pressure tanks according to examples 1 and 2 have a larger rupture pressure than the high-pressure tank according to comparative example 1. Therefore, when a high-pressure tank having the same level of rupture pressure as that of comparative example 1 was manufactured, it was possible to reduce the amount of fiber reinforced plastic used, reduce the weight of the high-pressure tank, and increase the hydrogen weight efficiency, as compared to comparative example 1. The burst pressures of examples 1 and 2 were determined based on the values of comparative example 1.

Further, fig. 7 shows the burst pressure of the high-pressure tank with respect to the position of the high-strength small-angle inner spiral layer formed by winding the high-strength fiber reinforced plastic. Fig. 8 shows the burst pressure of the high-pressure tank using the use area of the high-strength small-angle inner spiral layer with respect to the thickness area of the hemispherical portion. Each burst pressure value is determined based on the burst pressure value when the high-strength fiber-reinforced plastic is not used.

Referring to fig. 7, the burst pressure of the high-pressure tank varies according to the position of the high-strength small-angle inner spiral layer formed as a single layer by winding the high-strength fiber reinforced plastic once based on the thickness of the hemispherical portion. In particular, when the high-strength small-angle inner spiral layer is provided as any one layer in a thickness region corresponding to about 5% to 30% of the thickness of the hemispherical portion, the burst pressure increases. When the high-strength small-angle internal helical layer is provided as any one of the layers in the thickness region corresponding to about 15% to 25% of the thickness of the hemispherical portion, the burst pressure is significantly increased.

Referring to fig. 8, when the high-strength small-angle internal helical layer is formed by completely winding the high-strength fiber reinforced plastic in a thickness region corresponding to about 0% to 30% of the thickness of the hemispherical portion, the burst pressure of the high-pressure tank is increased as compared to the case where the high-strength fiber reinforced plastic is not used and the case where the high-strength fiber reinforced plastic is wound in another thickness region.

In the case where the rupture pressure of the high-pressure tank when the hemispherical portion is formed using the low-strength fiber-reinforced plastic without using the high-strength fiber-reinforced plastic is about 1.00, the rupture pressure of the high-pressure tank when the high-strength fiber-reinforced plastic is wound in a thickness region corresponding to about 0% to 30% of the thickness of the hemispherical portion is 1.11. When the high-strength fiber reinforced plastic is wound in a thickness region corresponding to about 31 to 100% of the thickness of the hemispherical portion, the burst pressure of the high-pressure tank is 1.10.

When the high-strength fiber reinforced plastic is completely used for the thickness region corresponding to about 0% to 30% of the thickness of the hemispherical portion as described above, the burst pressure of the high-pressure tank is increased as compared to the case of using the low-strength fiber reinforced plastic without using the high-strength fiber reinforced plastic. Even with a minimum amount of high-strength fiber-reinforced plastic, a higher burst pressure of the high-pressure tank can be obtained, compared to the case where high-strength fiber-reinforced plastic is entirely used for a thickness region corresponding to about 31% to 100% of the thickness of the hemispherical portion.

Therefore, it can be seen that, according to the present application, the effect of increasing the burst pressure of the high-pressure tank can be obtained by using the high-strength fiber reinforced plastic in a predetermined region of the hemispherical portion based on the thickness of the hemispherical portion. The present application is described in detail with reference to exemplary embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the application, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A high pressure tank, comprising:

a support layer defining an outer layer of the high pressure tank and including a cylindrical body part in a middle portion thereof, wherein the cylindrical body part is formed to have a structure in which a hoop layer and a spiral layer are alternately laminated, the hoop layer and the spiral layer being laminated on an outer surface of a gasket layer, wherein one of the hoop layers is first laminated to be located at an outer surface of the gasket layer, the outer surface of the gasket layer being in direct contact with the one hoop layer;

hemispherical portions formed on both sides of the cylindrical portion, wherein the hemispherical portions include a small-angle inner spiral layer portion as an inner layer and a small-angle outer spiral layer portion as an outer layer,

wherein the hemispherical portion includes only a small-angle inner helical layer portion without any hoop layer, the small-angle inner helical layer portion including a plurality of small-angle inner helical layers,

wherein at least one of the plurality of small-angle inner spiral layers has a greater rigidity and strength than any other of the plurality of small-angle inner spiral layers of the small-angle inner spiral layer portion and has a greater rigidity and strength than any layer of the small-angle outer spiral layer portion;

wherein the at least one small-angle inner spiral layer having greater rigidity and strength than any other of the plurality of small-angle inner spiral layers is provided as any layer within a thickness region corresponding to 15% to 25% of the thickness of the hemispherical portion such that the at least one small-angle inner spiral layer is completely wrapped around the hemispherical portion in the thickness region.

2. The high-pressure tank according to claim 1, wherein the small-angle inner spiral layer portion is formed in a thickness area corresponding to 5% to 30% of an entire thickness of each hemispherical portion.

3. The high-pressure tank as claimed in claim 1, wherein the small-angle outer helical layer portion is formed in a thickness region corresponding to 70% to 95% of the entire thickness of the hemispherical portion.

4. The high pressure tank of claim 1, wherein a portion of the plurality of small-angle inner helical layers of the small-angle inner helical layer portion is a high-strength small-angle inner helical layer having a relatively high rigidity, and the remaining small-angle inner helical layers are low-strength small-angle inner helical layers having a relatively low rigidity.

5. The high pressure tank of claim 4, wherein the high strength small angle inner helical layer is disposed as an outer layer of the small angle inner helical layer portion, and wherein all of the low strength small angle inner helical layer is disposed as an inner layer of the small angle inner helical layer portion.

6. The high pressure tank of claim 4, wherein the high strength small angle internal helical layer and the low strength small angle internal helical layer are disposed in a mixed pattern without limiting the order of lamination of the layers.

7. The high-pressure tank according to claim 4, wherein the high-intensity small-angle inner helical layer and the low-intensity small-angle inner helical layer are provided in a mixed pattern in which layers are alternately laminated to each other.

8. The high pressure tank of claim 1, wherein the low angle inner helical layer portion is configured by a high strength low angle inner helical layer.

9. The high-pressure tank according to claim 1, wherein the high-strength small-angle inner helical layer is provided as a bottom layer of a small-angle inner helical layer portion.

10. The high-pressure tank according to claim 1, wherein the hemispherical portion is formed by winding the fiber reinforced plastic around the gasket layer and the outer surface of the metal flange at an acute angle in a predetermined range with respect to a central axis direction of the high-pressure tank.